diff --git a/device_mapper/ioctl/libdm-iface.c b/device_mapper/ioctl/libdm-iface.c
index 1321dc008..eb6e9dbf3 100644
--- a/device_mapper/ioctl/libdm-iface.c
+++ b/device_mapper/ioctl/libdm-iface.c
@@ -471,6 +471,7 @@ static void _dm_zfree_string(char *string)
 {
 	if (string) {
 		memset(string, 0, strlen(string));
+		asm volatile ("" ::: "memory"); /* Compiler barrier. */
 		free(string);
 	}
 }
@@ -479,6 +480,7 @@ static void _dm_zfree_dmi(struct dm_ioctl *dmi)
 {
 	if (dmi) {
 		memset(dmi, 0, dmi->data_size);
+		asm volatile ("" ::: "memory"); /* Compiler barrier. */
 		free(dmi);
 	}
 }
diff --git a/libdm/ioctl/libdm-iface.c b/libdm/ioctl/libdm-iface.c
index 002669e8d..b195c115f 100644
--- a/libdm/ioctl/libdm-iface.c
+++ b/libdm/ioctl/libdm-iface.c
@@ -469,6 +469,7 @@ static void _dm_zfree_string(char *string)
 {
 	if (string) {
 		memset(string, 0, strlen(string));
+		asm volatile ("" ::: "memory"); /* Compiler barrier. */
 		dm_free(string);
 	}
 }
@@ -477,6 +478,7 @@ static void _dm_zfree_dmi(struct dm_ioctl *dmi)
 {
 	if (dmi) {
 		memset(dmi, 0, dmi->data_size);
+		asm volatile ("" ::: "memory"); /* Compiler barrier. */
 		dm_free(dmi);
 	}
 }